Methods for preparing copper nanowires from solution have been reported. See, for example, M. Figlarz; C. Ducamp-Sanguesa; F. Flievet; J. P. Lagier, Adv. Powder Metallurgy & Particulate Metals, 1992, 1, 179-92; Y. Chang, M. L Lye, and H. C. Zeng, Langmuir, 2005, 21, 3746; Y. Xia, Y. Xiong, B. Lim, S. E. Skrabalak, Angew. Chem. Int. Ed., 2009, 48, 60; A. R. Rathmell, S. M. Bergin, Y-L Hua, Z-Y Li, and B. J. Wiley, Adv. Mater., 2010, 22, 3558; A. R. Rathmell and B. J. Wiley, Adv. Mater., 2011, 23, 4798; and B. J. Wiley, “Solution-Coatable Transparent Conductive Films of Copper Nanowires,” presentation at 2012FLEX Flexible Electronics & Displays Conference & Exhibition, February 2012, each of which is hereby incorporated by reference in its entirety. Such methods can employ highly reactive reagents, such as hydrazine, and highly corrosive solutions, such as concentrated NaOH solutions. The nanowires produced from such methods have been reported to have large attached nanoparticles.
The applicant has discovered methods for readily preparing copper nanowires without resorting to highly reactive reagents, highly corrosive solutions, high temperatures, or long reaction times. Nanowires produced from such methods are free of large attached nanoparticles and are therefore expected to be more suitable for solution coating in electronics applications than previously disclosed copper nanowires.
Because of the relative abundance and lower cost of copper relative to silver, such improved methods may allow substitution of superior morphology copper nanowires in applications that currently rely on silver nanowires.